Refrigeration apparatus



Feb. 24, 1942. 7 E. B. MILLEIQ 2,274,613

REFRIGERATJION APPARATUS Filed March 4, 1939 s Sheets-Sheet 1 awe/Wm Feb. 24, 1942. E. B. MILLER REFRIGERATION APPARATUS Filed March 4, 1939 3 Sheets-Sheet 5 Patented Feb. 24, 1942 OFFICE.

2,274,613 REFRIGERATION APPARATUS Ernest B. Miller, Annapolis, Md., assignor to William Burnet Wright, Baltimore, Md.

Application March 4, 1939, Serial No. 259,921

Claims.

gether and furthermore such frosting interferes with the structural parts of the machine and the operation of the mechanical parts.

One of the principal objects of the invention is to eliminate frosting so as to protect the mechanical and structural parts of the machine and prevent the freezing together of the articles to be vended.

The preferred form of theinvention relatesto the type of apparatus wherein solid carbon dioxide rests on a fixed plate. A metal contactor plate is movabl into and out of contact with said fixed plate, such movement being controlled by a thermostat. Heat transfer members are disposed in the space to be refrigerated and means is provided to conduct heat-from the members to the contactor plate.

Another object of the invention is to provide an improved form of heat conductor for transferring heat from the heat transfer members or member to the contactorplate.

Another object of the invention is to provide a vending machine designed to insure maximum intervals of time between servicings with the refrigerant, as such servicing constitutes one of the main operating expenses. One charge of 50 pounds of solid carbon dioxide will maintain the machine of the present invention at about 10 F. for a period of from 4 to 7 days.

Another object of the invention is to provide a carefully regulated control over the temperature of the merchandise being vended so that such articles as ice cream may always be in a condition permitting immediate consumption tomer. v

A further object of the invention is to provide a vending machine with a plurality of magazines to accommodate a variety of articles such as ice creams of different flavors and so arranged that by the cus- 'the customer can readily select the desired article.

Other objects and features of novelty will be apparent from the description taken in connection with the drawings in which Fig. l is a vertical section through one embodiment of the invention.

Fig. 2 is a horizontal sectional view taken substantially onthe line 2-2 of Fig. 1 and looking in the direction indicated by the arrows.

Fig. 3 is a plan view of the contactor plate and conductors. I Fig. 4 is a perspective view of one of the conductors, and

Fig. 5 is a perspective view of another form of conductor.

Referring to the drawings which illustrate the invention as embodied in a vending machine, [0 indicates an outside container very thoroughly insulated and supported on the members II. It will-be noted that this container also has its bottom and top walls thoroughly insulated and, as shown in Fig. 2, is substantially octagonal in plan view. Supported on a vertical shaft l2 extending through the bottom wall of theouter container is a turntable l3 carrying a number of magazines I4 supported on the table by the brackets l4 and vertical rods [5. The present invention is illustrated as adapted for a machine vending ice cream in cups l6. These cups are arranged in vertical columns and carried by the magazines l4. There are a plurality of them arranged in a circular series, as shown in Fig. 2. The different columns may comprise cups carrying ice cream of difierent flavors. Of course, other articles could be arranged in a similar manner. The turntable I 3 may be rotated -by means of the gearing l1 and. I8, shaft 19 and hand wheel 20 so as to bring any magazine opposite the vending outlet. Fitted to the bottom of each magazine is a trippei' mechanism 2i actuated by the horizon-- tal movement of cam 22 when the door 23 is moved to its open position. It will be understood that the tripper 2! supports the column of cups. At the top of the container l0 there is provided a hatch 24 for charging the magazines.

Disposed within the columns of cups is a second container 25 supported in any suitable manner from the top of the first container and having a bottom 26. Within this container is a shell- 21 and having a fixed metal bottom 28 adapted to support solid carbon dioxide or the like 29. In order that this second container may be charged .with the solid refrigerant, a removable insulated hatch 30 is provided. Immediately under the fixed metal bottom is a metal contactor plateSl movable into and out of contact with the fixed bottom. For this purpose the contactor heat transfer.

(not shown) plate is pivoted at 32 to one end of a bell crank lever 33 pivoted at 34. The vertical leg 35 of this bell crank is connected to the plunger rod 36 of a Sylphon bellows 31 which is in communication with the 'bulb 38 by means of tube 39. A volatile liquid in bulb 38 exerts variable pressures on the Sylphon bellows according to the temperatures to which the bulb 38 is subjected and thereby moves the thermostat plunger 36 either to the right or left depending on whether the temperature has decreased or increased. This movement through "25 are the finned heat transfer members 40.

These are supported in a suitable manner on the brackets 4| which in turn are in heat transfer communication with the contactor plate 3| through the flexible heat conductors 42. As clearly shown in Fig. 4, these conductors comprise fiexible fiat metal strips 43 of braided heat conducting metal wire such as copper bent to suitable shape. They are spaced throughout their lengths and fastened together at their ends and provided with the holes 44 and 45 for the cap screws 46 and 41 respectively. As clearly shown in Fig. 3, there are a plurality of these flexible heat conductors.

The heat conductors of the present invention afford a very efficient heat transfer means and being flexible and in spaced-strips, offer a minimum of resistance to the movement of the contactor plate in response to the thermostat in the refrigerated space.

It will be noted that the opening 48 through 53 movable with the door. The shaft 54 is operated by the customer and carries a cam 55. This cam is so constructed that a coin must be present between the same and a finger 56 on the latch 5| in order to effect the lowering of the latter. A slight turning of shaft 54 in a counterclockwise direction efiects this lowering when a coin is present. Mounted rigid with shaft 54 is an arm 51 at its free end carrying an arcuate member 58 having'an arcuate slot 59 therein, in which is positioned a pin 60 on lever 6| connected to the door at one end and loosely mounted on shaft 54 at the other. The first counterclockwise rotation of shaft 54 frees latch 5|. Further rotation'of shaft 54 in acounterclockwise direction carries the arcuate member 58 so that pin 60 strikes the'right hand end of slot 59 and acwhich the rod 36 extends is larger in diameter than the rod thereby providing an unrestricted communication between the two containers that is to say, the solid ice container and the container having a space to be refrigerated. It. follows that CO2 gas evaporated from the solid carbon dioxide can pass from the inner container into the outer container, thereby any atmospheric air present in the. refrigerating space or outer container will be displaced by the heavy CO2 gas'so that no moisture is present to cause frosting. Heretofore one of the principal defects in refrigcrating apparatus employing solid carbon dioxide has been due to frosting of mechanical parts and/or the articles being refrigerated. In the present instance, if atmospheric air were not eliminated from the space being refrigerateithe cups containing the ice cream might freeze togethe'r. It will be noted that the contactor plate and bottom 28 of the inner container are in an atmosphere of CO2 gas and so no frosting collects on the same to interfere with an efficient The excess carbon dioxide gas collecting in the outer container may be vented by leaking past the filled hatch 24 or by any other suitable vent at the top of the outer container This feature of preventing frosting of the mechanical parts of the apparatus and tuates lever 6| to open the door 23.

Movement of the door 23 causes cam 22, through arms 62 and 63 to move the latch 2| in a direction to release the bottom cup l6 of ice cream. Movement of the latch 2| is effected against the resistance of spring 64 as it carries an upper arm 65 engaging the latter. When the latch 2| moves spring 64 it alsomoves a pin 66 through the wall of the magazine to hold the next cup from falling down. When the door is closed of course latch 2| returns to its normal position and pin 66 moves to release the cup it is holding.

Fig. 5 illustrates another form of conductor comprising a flexible cable 43' of braided heat rality of substantially U-shaped superposed flexible strips of braided metal wire spaced from each articles being refrigerated constitutes an important feature of my invention.

The door 23 is mounted on rollers -70 1 49 and moves horizontally to control the vending outlet other through the greater part of their lengths,

their free ends being/ fastened together as by- It is important that the door 23 close the delivery opening so that there will be no leakage of carbon dioxide out by the same, thus admitting air and resulting in possible frosting. It is also important that the door be closed as soon as possible after the delivery of a package, otherwise the heavy carbon dioxide gas will flow out through the delivery opening, be replaced by air, and result in frosting due to the moisture in the air. To eliminate leakage of the carbon dioxide gas, as far as possible, a heavy coil spring 10 is attached at one end to cam member 22 rigid with package. In order to make a gas tight joint between the door and the container packing 1| may be employed.

Although the form of the invention has been described in detail, it is to be understood that it is not thus limited but includes modifications and changes that come within the scope of the appended claims.

I 'am aware of Patents No. 1,901,000 and No. 1,937,690 and do not claim anything shown in these patents.

a flexible heat conductor connecting the 2. The improvement according to claim 1 wherein the conductor comprises flat metal strips spaced throughout their lengths and fastened together at their ends.

3; The improvement according to claim I wherein the conductor comprises a braided cable. 4. The improvement according to claim 1 wherein the conductor comprises fiat strips oi. braided metal wire ,spaced throughout their lengths and fastened together at their ends.

5. In apparatus of the character described comprising a container having a fixed metal bottom adapted to support solid carbon dioxide, a metal contactor plate movable into and out of contact with said bottom, a thermostat in the space to be refrigerated controlling such' movement, a heat transfer member in the space to be refrigerated, a flexible heat conductor connecting the plate and member, a, chamber in which the contactor plate is disposed and means providing communication between the part of the container above the solidcarbon dioxide and said chamber whereby all air is displaced from said chamber by carbon dioxide gas evaporating from the solid carbon dioxide and thereby eliminates frosting of the conigctor plate and the bottom of the container.

ERNEST B. MILLER. 

